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1995 Vol. 17, No. 4
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1995, 17(4): 337-344.
Abstract:
The paper reveals the relation between linear AND-OR gate and the Emitter Function Logic (EFL). With theoretic calculation and PSPICE simulation, the paper proves that the linear AND-OR gates can work at super-high-speed and can be multi-cascaded. On the basis of analyzing the high-speed switch units which coordinate with linear AND-OR gates, two kinds of Emitter Coupled Logic (ECL) circuits are designed. The paper also discusses the design principle of super-high-speed digital circuits and some examples of combinational and sequential circuits using linear AND-OR gate are given.
The paper reveals the relation between linear AND-OR gate and the Emitter Function Logic (EFL). With theoretic calculation and PSPICE simulation, the paper proves that the linear AND-OR gates can work at super-high-speed and can be multi-cascaded. On the basis of analyzing the high-speed switch units which coordinate with linear AND-OR gates, two kinds of Emitter Coupled Logic (ECL) circuits are designed. The paper also discusses the design principle of super-high-speed digital circuits and some examples of combinational and sequential circuits using linear AND-OR gate are given.
1995, 17(4): 345-351.
Abstract:
The balanced operational amplifier including its merits and designing methods is discussed by comparing its performance to a conventional differential output amplifier when used in a single balanced stage. A new balanced OTA circuit design is also presented.
The balanced operational amplifier including its merits and designing methods is discussed by comparing its performance to a conventional differential output amplifier when used in a single balanced stage. A new balanced OTA circuit design is also presented.
1995, 17(4): 352-358.
Abstract:
The dynamic properties of continuous unsymmetic neural networks are discussed, and the condition of existence of unique equilibrium point is obtained. The conditions not producing static state bifurcation and Hopf bifurcation are put forward and the sufficient conditions of overall asymptotic stability and exponential stability are obtained.
The dynamic properties of continuous unsymmetic neural networks are discussed, and the condition of existence of unique equilibrium point is obtained. The conditions not producing static state bifurcation and Hopf bifurcation are put forward and the sufficient conditions of overall asymptotic stability and exponential stability are obtained.
1995, 17(4): 359-364.
Abstract:
A new mathematical methodinterval analysis is applied as a tool for fault diagnosis in a tolerance network. The adequate selection of accessible nodes for fault diagnosis at subnetwork-level is investigated by using the method. This is a key problem often encountered in the engineering.
A new mathematical methodinterval analysis is applied as a tool for fault diagnosis in a tolerance network. The adequate selection of accessible nodes for fault diagnosis at subnetwork-level is investigated by using the method. This is a key problem often encountered in the engineering.
1995, 17(4): 365-371.
Abstract:
Two intracell C/I balancing techniques are presented for controlling mobiles transmitter powers on the uplinks of a multi-cell cellular CDMA (Code Division Multiple Access) system in order to compensate the combined effects of shadowing and path loss, with their performance being evaluated in terms of cell-averaged outage probability which is different from the traditional index.
Two intracell C/I balancing techniques are presented for controlling mobiles transmitter powers on the uplinks of a multi-cell cellular CDMA (Code Division Multiple Access) system in order to compensate the combined effects of shadowing and path loss, with their performance being evaluated in terms of cell-averaged outage probability which is different from the traditional index.
1995, 17(4): 372-377.
Abstract:
Based on the analysis of Adaptive Moving Target Indication (AMTI), and the signal processing of Synthetic Aperture Radar (SAR), a complete compatible system of AMTI and SAR is put forward. The compatibility and effectiveness of this system is proved in theory. The resutls of simulation show that this system not only has the good ability of imaging stationary targets but also has the ability of detecting moving targets under the background of strong clutter.
Based on the analysis of Adaptive Moving Target Indication (AMTI), and the signal processing of Synthetic Aperture Radar (SAR), a complete compatible system of AMTI and SAR is put forward. The compatibility and effectiveness of this system is proved in theory. The resutls of simulation show that this system not only has the good ability of imaging stationary targets but also has the ability of detecting moving targets under the background of strong clutter.
1995, 17(4): 378-384.
Abstract:
A new time domain finite difference method with variable grids of high accuracy is derived by the polynomial approximation, and applied to analyze the variable-angle transmission line discontinuities. The method has the advantages of comparatively less memory space and CPU time, and is much simpler than other techniques. Test results are in good agreement with published data, thereby the accuracy of the new method is verified.
A new time domain finite difference method with variable grids of high accuracy is derived by the polynomial approximation, and applied to analyze the variable-angle transmission line discontinuities. The method has the advantages of comparatively less memory space and CPU time, and is much simpler than other techniques. Test results are in good agreement with published data, thereby the accuracy of the new method is verified.
1995, 17(4): 385-390.
Abstract:
The characteristics of coherent radiation produced by a cylindrical electron beam passing through a rectangular waveguide and linearly polarized wig-gler is studied. The instability analysis is based on the linearized Vlasov-Maxwell equations for the perturbations about a self-consistent beam equilibrium. The dispersion equation of TMmn mode is deduced and by making use of numerical calculation the radiation frequency and growth rate as a function of electron beam energy and radius, axial magnetic field, wiggler field and wave lengthare presented and discus sed.
The characteristics of coherent radiation produced by a cylindrical electron beam passing through a rectangular waveguide and linearly polarized wig-gler is studied. The instability analysis is based on the linearized Vlasov-Maxwell equations for the perturbations about a self-consistent beam equilibrium. The dispersion equation of TMmn mode is deduced and by making use of numerical calculation the radiation frequency and growth rate as a function of electron beam energy and radius, axial magnetic field, wiggler field and wave lengthare presented and discus sed.
1995, 17(4): 391-396.
Abstract:
Bistatic scattering of a perfectly conducting semicylinder is analysed by using a hybrid method. In the hybrid method, the currents in the close vicinity of edges are represented as unknown coefficients; the first-order currents on the curved face are obtained by Fock theory; the high-order currents are described as the Fock type functions involving two unknown coefficients. The first-order currents on planar surface are physical optical currents and diffraction currents obtained by the uniform geometrical theory of diffraction form involving two unknown coefficients. The magnetic field equation is solved to obtained four coefficients and the currents in the close vicinity of the edges. The results obtained by the hybrid method are in good agreement with the results of moment method.
Bistatic scattering of a perfectly conducting semicylinder is analysed by using a hybrid method. In the hybrid method, the currents in the close vicinity of edges are represented as unknown coefficients; the first-order currents on the curved face are obtained by Fock theory; the high-order currents are described as the Fock type functions involving two unknown coefficients. The first-order currents on planar surface are physical optical currents and diffraction currents obtained by the uniform geometrical theory of diffraction form involving two unknown coefficients. The magnetic field equation is solved to obtained four coefficients and the currents in the close vicinity of the edges. The results obtained by the hybrid method are in good agreement with the results of moment method.
1995, 17(4): 397-403.
Abstract:
The general field expressions for conformal microstrip antennas on cylindrical body are derived based on dyadic Green s functions for concentric-cylindrical layered media. The radiation patterns for various radii, permittivities, and thickness of the dielectric layer of a microstrip wrap-around antenna are obtained using the general field expressions and electric surface current model.
The general field expressions for conformal microstrip antennas on cylindrical body are derived based on dyadic Green s functions for concentric-cylindrical layered media. The radiation patterns for various radii, permittivities, and thickness of the dielectric layer of a microstrip wrap-around antenna are obtained using the general field expressions and electric surface current model.
1995, 17(4): 404-411.
Abstract:
Recently, Higher-order statistics have become powerful tools in signal processing field and have been applicable in harmonic retrieval. This paper first analyses the existing correlation-based methods for harmonic retrieval; then summarizes the newly developed higher-order statistics-based approaches and pre-filtering-based methods with hybrid higher-order statistics for estimating parameters of harmonics in noise. It is shown that higher-order statistics-based approaches are superior to correlation based approaches in restraining colored noise and retrieving useful information of harmonics.
Recently, Higher-order statistics have become powerful tools in signal processing field and have been applicable in harmonic retrieval. This paper first analyses the existing correlation-based methods for harmonic retrieval; then summarizes the newly developed higher-order statistics-based approaches and pre-filtering-based methods with hybrid higher-order statistics for estimating parameters of harmonics in noise. It is shown that higher-order statistics-based approaches are superior to correlation based approaches in restraining colored noise and retrieving useful information of harmonics.
1995, 17(4): 412-416.
Abstract:
Characteristic varibles of waveform vector quantizer of speech signal are presented and used to analyze codebook and its training sequence. It includes three parts, i. e., constructing initial codebook efficiently, training codebook fast and quantizing input vectors fast. Computer simulations show that the training speed of codebook is quickened by the new design algorithm and the complexity of vector quantizer is reduced.
Characteristic varibles of waveform vector quantizer of speech signal are presented and used to analyze codebook and its training sequence. It includes three parts, i. e., constructing initial codebook efficiently, training codebook fast and quantizing input vectors fast. Computer simulations show that the training speed of codebook is quickened by the new design algorithm and the complexity of vector quantizer is reduced.
1995, 17(4): 417-420.
Abstract:
This paper disscusses the principle and design of the implementation of a compression storage system for screen graphics-letter. The new system overcomes the shortage of screen storage, and possesses a large compression ratio and a high operating speed.
This paper disscusses the principle and design of the implementation of a compression storage system for screen graphics-letter. The new system overcomes the shortage of screen storage, and possesses a large compression ratio and a high operating speed.
1995, 17(4): 421-425.
Abstract:
By using the apparatus given in this paper the experiment on photo-conductive switches was conducted to investigate the affection of both the laser energy and bias voltage on switch output. By means of the same set-up, the carrier lifetime of Cr: GaAs used was measured to be as 1.8ns, and the possibility of the set-up to be utilized as a high speed photodetector has been demonstrated.
By using the apparatus given in this paper the experiment on photo-conductive switches was conducted to investigate the affection of both the laser energy and bias voltage on switch output. By means of the same set-up, the carrier lifetime of Cr: GaAs used was measured to be as 1.8ns, and the possibility of the set-up to be utilized as a high speed photodetector has been demonstrated.
1995, 17(4): 426-429.
Abstract:
A simple graphic method for obtaining the real and imaginary parts of the propagation constant of metal-clad planar optical waveguides is presented. This method is straightforward, accurate and valuable
A simple graphic method for obtaining the real and imaginary parts of the propagation constant of metal-clad planar optical waveguides is presented. This method is straightforward, accurate and valuable
1995, 17(4): 430-433.
Abstract:
This paper gives the analytic solutions of axisymmetrical field in a nonlinear longitudinally inhomogeneous self-focusing fiber by using the variational method. The variational solutions are in good agreement with the results of the other references in the case of linear condition.
This paper gives the analytic solutions of axisymmetrical field in a nonlinear longitudinally inhomogeneous self-focusing fiber by using the variational method. The variational solutions are in good agreement with the results of the other references in the case of linear condition.
1995, 17(4): 434-437.
Abstract:
Transient EM field scattering by underground objects using finite-difference method in time-domain (FDTD) is calculated, and object s response of an EM pulse related to dielectric parameters and underground structure is presented. Conclusions of this method can be used as theoretical evidences of object detecting and discriminating. The method can be applied to circumstances of arbitrary cylinder objects and two-dimensional underground structure, and can be developed to three-dimensional circumstances.
Transient EM field scattering by underground objects using finite-difference method in time-domain (FDTD) is calculated, and object s response of an EM pulse related to dielectric parameters and underground structure is presented. Conclusions of this method can be used as theoretical evidences of object detecting and discriminating. The method can be applied to circumstances of arbitrary cylinder objects and two-dimensional underground structure, and can be developed to three-dimensional circumstances.
1995, 17(4): 438-442.
Abstract:
The E-plane waveguide branch directional couplers are analysed by a method which combines the multi-mode network theory with rigorious mode matching approach. The electromagnetic field components are expanded by the superposition of LSEx modes rather than TE and TM modes in the mode matching procedure. Meanwhile, the electromagnetic problem is transferred into the network problem through the mode matching treatment. It is shown that the present method has the advantages of simplicity and less computation with unaffecting the accuracy of the calculation.
The E-plane waveguide branch directional couplers are analysed by a method which combines the multi-mode network theory with rigorious mode matching approach. The electromagnetic field components are expanded by the superposition of LSEx modes rather than TE and TM modes in the mode matching procedure. Meanwhile, the electromagnetic problem is transferred into the network problem through the mode matching treatment. It is shown that the present method has the advantages of simplicity and less computation with unaffecting the accuracy of the calculation.
1995, 17(4): 443-448.
Abstract:
The error functions of CCII-based integrators are analysed. On this basis, the fully integrated CCII-based continuous-time bandpass filters consisted of double integrator loops are studied, and the relationship between the centre frequency p and Qp and the magnitude E and the phase E of the error function is also discussed. The effects of nonideal CCII are considered in detail. The conclusions obtained may provide foundation and improvement for the design of CCII-based MOSFET continuous-time higher order filters.
The error functions of CCII-based integrators are analysed. On this basis, the fully integrated CCII-based continuous-time bandpass filters consisted of double integrator loops are studied, and the relationship between the centre frequency p and Qp and the magnitude E and the phase E of the error function is also discussed. The effects of nonideal CCII are considered in detail. The conclusions obtained may provide foundation and improvement for the design of CCII-based MOSFET continuous-time higher order filters.
